Conventionally, a projector that modulates a light beam irradiated by a light source in accordance with image information to form an optical image by a modulator and projects the optical image in an enlarged manner has been known.
In such a projector, since luminance of the light source is increased, an exhaust structure for exhausting air heated by the light source with its temperature increasing has been employed (for example, see JP Hei11-354963A).
According to this exhaust structure, a sirocco fan is applied as a centrifugal fan that exhausts the air inside the projector to the outside.
More specifically, the sirocco fan is arranged such that a suction side thereof is along an optical path plane defined by a light source device, an optical modulator and a projection optical device.
The sirocco fan sucks the air heated by the optical modulator, the light source device and the like located above a suction hole thereof, and discharges the air in a projection direction of a light beam from the projection optical device via an exhaust hole of the projector, i.e., in a direction from the front side of the projector to the outside.